The present invention relates to a cage-type stranding machine of the type which includes a rotor equipped with a throughgoing supporting pipe rotatably mounted at both ends and supporting, concentrically with the rotor axis, several spool carriers holding spools for the filaments to be stranded in a manner so as to be rotatable and drivable.
In cage-type stranding machines of the above-mentioned type at least two circular plates, depending on the number of spool carriers required, are disposed at the supporting pipe. The spool carriers are held in these plates so as to. rotate about their longitudinal axes. The longitudinal axes of the spool carriers are oriented parallel to the rotor axis while the axes of rotation of the spools held by the spool carriers extend perpendicularly thereto. Between the two carrier plates, several spool carriers are arranged in uniform distribution about the circumference. These spool carriers are coupled with one another by way of a drive system so that they revolve relative to the rotor if the rotor rotates. This generally occurs in such a way that, with the rotor rotating, the axes of the spools remain oriented parallel to one another and parallel to the plane of the floor.
Due to the dimensions of the spools, the axes of rotation of the spool carriers must be placed at a considerable distance from the supporting pipe so as to even permit the above-described position relative to the rotor. This results in a considerable total diameter for the rotor as a whole, which ultimately leads to limitations regarding size and stability of the stranding machine.
Since the free space required for the rotary movement of the spool carriers, and the limitation on the total diameter of the rotor, require that certain limits be maintained, the diameter of the supporting pipe (which is decisive for the stability of the rotor) cannot be enlarged at will. The entire system becomes sensitive to bending vibrations, so that there are limitations with respect to the highest permissible rpm.